Coaxial connector



Fell 1959 B. H. GRIFFITHQJR 2,375,417

COAXIAL CONNECTOR Filed April 27, 1955 INVENTOR BEN H. GRIFFITH JR.

ATTORNEYS United States Patent COAXIAL CONNECTOR Ben H. Griliith, Jr., Baltimore, Md., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application April 27, 1955, Serial No. 504,394 3 Claims. (Cl. 333-34) The present invention relates to a coaxial connector and more particularly to a coaxial connector adapted to couple a coaxial transmission line to a wave guide.

Heretofore when coupling a coaxial line to a wave guide lateral force was required to make the connection giving rise to the possibility that a probe for coupling the energy in the coaxial line to the wave guide might be damaged or bent. Bending of the probe would be undesirable inasmuch as it must be parallel with the direction of the electric field which in TE modes takes a direction transverse to the direction of propagation in the guide, and damage such as cuts and burrs would disturb the propagated field configuration along the guide. Hence the coaxial line to the guide connection tended to be faulty and positive connections were difiicult to make.

This invention is directed to a coaxial connector which is operative to make the connection between a coaxial,

line and a wave guide while avoiding the disadvantages of the prior art. The connection is made without the application of lateral force which might tend to misalign or damage the probe, it is a positive connection and it may be made from a blind spot. This is accomplished by providing a flange type connector having an outer and inner conductor separated by insulating material. The inner conductor is interiorly threaded and has a split expandable section of reduced diameter at one end. This end is adapted to be received within a hole bored in a truncated cone which forms part of a probe within the waveguide. The connection is made by threading a bolt or the like into the split section thereby causing it to expand and make a positive connection with the cone.

An object of the present invention is the provision of a coaxial cable to wave guide connector.

Another object is to provide a coaxial connector which obviates the need for the application of any lateral force to connect a coaxial cable to a wave guide.

A further object is to provide a permanent positive and rugged coaxial to wave guide connector which will allow connections to be made from a blind spot.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a perspective view showing the cooperation of the coaxial connector and a wave guide system; and

Fig. 2 is a cross-sectional view of the connector drawn toascale of4zl.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a wave guide system generally designated by 3 for coupling energy between a transmitter, receiver and antenna (not shown).

The wave guide system comprises a pair of parallel wave guides 4 with thickened portions to which coaxial 2,875,417 Patented Feb. 24, 1959 connectors 6 may be secured and connected for the trans: fer of energy.

In the preferred embodiment, the connectors 6 and'the wave guides 4 are alike except for a right-hand and lefthand relationship, so that a description of any one should sufiice for both.

Each wave guide 4 comprises a wall having a circular aperture 9 for receiving the connector 6 and a truncated cone 5 on the wall opposite the wall having aperture 9; the cone 5 having its center axis aligned with aperture 9. The cone 5 facilitates the right angle turn of the i 13 therebetween.

electric field transferring energy between the wave guide 4 and the connector 6.

Each connector 6 comprises an inner conductor or sleeve 8, an outer conductor or sleeve 10 and insulation The-inner and outer conductors 8 and 10 and the insulation 13 are shaped to provide a strong unitary structure for the connector 6.

The outer conductor 10 has a flange 11 whereby the connector 6 is secured to the wave guide 4 by bolts or equivalent means, and has bayonet pins 12 adapted to be engaged by a complementary bayonet slot on the outer conductor of a coaxial cable (not shown). The flange 11 conductively connects the conductor 10 to the wave guide 4.

The inner conductor 8 of the connector 6 serves as a probe and is connected to the cone 5. To this end, as

illustrated in Fig. 2, the cone 5 has a bore 7 for receiving the inner conductor 8. The inner conductor 8 is hollow and has a split section 14 at one end, a split section 15 at the other end, and an intermediate section 17. In a specific embodiment the section 15 was long.

The split section 14 is adapted to couple to the inner conductor of the coaxial cable. The insulation 13 has a slightly enlarged hole about the section 14 to allow for play of the prongs of the section 14.

The split section 15 comprises four uniformly-thick slots 16 disposed apart and consequently has four prongs. The outer diameter of section 15 is the same or preferably very slightly less than that of bore 7, and is smaller than that of the intermediate section 17. The section 15 and a contiguous part of the section 17 are threaded on the inside and receive a tightening Allen bolt 18 or the like which can be turned by a tool inserted through open end 19 of the inner conductor 8. In assembly the Allen bolt is moved to the right with respect to Fig. 2, the prongs of section 15 are compressed and inserted in bore 7 of cone 5. The Allen bolt 18 is turned to tighten the prongs against cone 5 after the connector 6 is attached to the wave guide 4. In this way a solid permanent contact is made between the inner conductor 8 and cone 5 although these parts are not visible in the assembly.

Should it be desired to close off one of the wave guides 4 at any time, a closing cap 20' held to the systern 3 by a chain 21 can be removably attached, being provided with a bayonet slot complementary to pins 12.

It can be seen that the connection between cone 5' coupled to the connector without the danger of damaging or misaligning the probe. Thus a positive coaxial cable connection to a wave guide may be made from a blind spot without the necessity of applying lateral forces.

Obviously many modifications and variations of the present invention are possible in light of the above.

teachings. It is therefore to be understood that within the scopeof the appended claims, the invention may be practiced-otherwise-than as specifically describedw What is claimed is: by

1. In combination, a wave guide having a cone mounted therein opposite an aperture "in-the guide, said cone having a circular bore therein of a predetermined diameter facing said aperture, a coaxial connector comprising inner and outer sleeves, said outer sleeve being fixedly secured to the exteriorof said guide about said aperture, said inner sleeve having an interiorly threaded portion; said-inner sleeve and threaded portion having a longitudinally slotted end 'section-havingan outer diameter less than saidpredetermineddiameter, said end section being adapted to extend intosaid 'wave guide and withinsaid here in non-contacting relation; and means within said inner sleeve adapted'to cause said end section to expand whereby said end section contacts the walls of saidbore.

2; In combinationwith a wave guide havingan apex ture 'in'one wall thereof, said'wave guide having a cone mounted'therein on a Wall opposite said aperture, said cone having a bore therein facing'said aperture, a coaxial connector for enabling connection of a coaxial lineto said wave guide comprising a hollow inner conductor and a hollow outer conductor insulated there-' between, means-on said outer conductor adapted to be permanently fixedly secured to said wave guide about said aperture, said inner conductor having an interiorly 4 means on the other end of said connector adapted to couple a coaxial line to said connector.

3. In combination, a wave guide having an aperture in one wall thereof, an impedance-matching cone having the larger end mounted on a wall or" said wave guide opposite said aperture and the smaller end extending toward said aperture, said smaller end having a bore of predetermined diameter formed on a line coaxial with said aperture, a coaxial connector for enabling electrical connection of a coaxial cable to said wave guide comprising a hollow'outer conductor fastened by means of a flange to said wave guide about said aperture, a hollow inner conductor mounted, within said outer conductor and insulated therefrom having a longitudinally slotted end section on one end extending within said bore, said end section having a normal diameter less than said bore, said inner conductor having an interiorly threaded portion, an Allen bolt mounted in said threaded portion operable throughsaid inner conductor for expanding said'slotted end section whereby a positive connection may be made between said inner conductor and said cone, and means on the other end of said connector adapted to couple a coaxial line to said connector.

References Cited in the file of this patent UNITED STATESVPATENTS 1,894,984 Ericksen et al. Ian. 24, 1933 2,407,530 Bielski et al. Sept. 10, 1946 2,508,409 Lord May 23, 1950" 2,530,171 Okress Nov. 14, 1950 2,593,981 Capita Apr. 22, 1952 2,702,366 Ginzton Feb. 15, 1955 

